For many years, the owners' of boats and yachts have recognized the problem of marine growth on the submerged parts namely the hulls, propeller, propeller guard and shaft of their watercraft. This problem can be summarized in that a layer of marine algae and/or plankton and phosphate formation on the submerged part of the hull adversely affects the performance and efficiency of their vessels. This problem becomes more serious when a boat or yacht is left for periods of two or more weeks in the water without being moved. The problem is further aggravated when the boat remains in stagnant water. A fouling growth can significantly and adversely affect a boat or yacht's performance, increases fuel consumption and at times adversely affects a boat's balance when sailing. The growth can also lead to relatively extensive and expensively damage to parts of the engine or engines and at times become so serious as to cause removal of the watercraft from the water.
There are several solutions to avoid the aforementioned problem. The first and most straight forward solution is to move the boat at least twice each month and to operate the vessel at speed for at least about 5 miles over a period of at least 15 minutes. However, this is not always a practical solution. Scaling and cleaning the boat manually is another approach but can adversely affect the coating on the underside of a boat or yacht. Another approach is to remove the boat from the water, clean or scrap the hull and then apply a fresh undercoating. This approach which is generally successful is time consuming and expensive. Further, with smaller boats they can frequently be stored outside of the water, as for example on a lift.
A more recent approach for cleaning parts of the boat in water is disclosed in a U.S. Pat. No. 6,840,187 of Tible. As disclosed therein, an apparatus for cleaning the underwater portions of a boat having at least one cleaning unit with an injection element for generating a jet of cleaning fluid under high pressure and a manifold for generating jets of gas under low pressure. The manifold enables a space to be defined around the cleaning fluid jet in which space density is considerably reduced relative to the density of the surrounding water such as a space that is free or practically free from water. This space extends from the injection element to the surface for cleaning of the underwater portions. The apparatus is applicable for cleaning boats such as sail boats, motor boats and canal boats without it being necessary to take them out of the water.
A further approach for inhibiting fouling of an underwater surface is taught by Staerzl et al in U.S. Pat. No. 7,211,173. The Staerzl et al. patent discloses a marine fouling inhibiting system that includes first and second conductors which are made of a polymer matrix such as vinyl ester and a suspended conductor such as graphite powder or particles. This type of conductive material is formed to provide two sections of a boat hull so that a source of electrical current can be used to reversibly cause an electric current to flow to and from the conductive coating. The conductive coatings are electrically insulated from each other in order to force the formation of an electrical circuit which includes the two conductive coatings, the source of electrical current and the water in which the boat hull is disposed. This results in the creation of chlorine bubbles on the conductive surface. Chlorine bubbles on the boat hull surface discourage the formation of marine growth such as barnacles.
Notwithstanding the above it is presently believed that there is a need and a potential commercial market for an improved apparatus and method for inhibiting fouling of an underwater surface. It is also believed that the apparatus and method in accordance with the present invention will reduce the need for manually cleaning the underwater surfaces of boats and yachts, eliminate the need to operate watercraft periodically to avoid buildup on underwater surfaces, can be accomplished economically, will maintain the hull and engine parts in prestige condition and all of the above can be done without adversely affecting the environment.